1. Field of the Invention
The present invention relates generally to truck and/or trailer mounted portable devices and methods for dispensing pavement repair materials.
2. Description of the Prior Art
In the past, as many as three vehicles were sometimes needed to repair openings and potholes in asphalt, concrete and other roadway surfaces. One vehicle provided an air compressor for use with various pneumatic repair tools which were used to dress the hole, crack or cavity to be filled. Another vehicle contained liquid asphalt tack material which would be sprayed into the dressed cavity, and a third vehicle would deliver asphalt mix material to the cavity. The asphalt would then be packed, compacted and leveled by hand to complete the repair.
U.S. Pat. No. 4,196,827, issued Apr. 8, 1980, entitled "Portable Machine For Transporting Heated Asphalt Products For Use In Repairing Asphalt Pavement" shows a portable machine which was designed to incorporate all phases of the pavement repair into one mobile unit. The machine has a hopper for transporting asphalt mix, and a reservoir below the hopper having a heat source. The reservoir contained liquid asphalt tack material. The heat source is used to heat the liquid tack material, and the tack material is used to heat the asphalt mix in the hopper by heat transfer. Asphalt tack material is also dispensed from the tack material tank by means of spray equipment connected to a discharge valve on the rear of the truck.
In spite of being less expensive to operate in terms of material and labor, the previously described device possessed several different disadvantages. Many of these disadvantages related to the type of repair material utilized and the fact that multi-component materials were required to do each job. Because multiple component materials were required for each patch job, the equipment used for transporting such components was complicated and often limited in versatility. For example, the liquid asphalt tank carried on the unit was suitable for road oils and cutbacks but was not well suited for use with asphaltic cements. Also, in the case of the device described in the '827 patent, the liquid asphalt tank was not suited for use with asphalt emulsions, because the volatile contents of the emulsions would be driven off and dry out the materials.
U.S. Pat. No. 4,944,632, issued Jul. 31, 1990, and assigned to the assignee of the present invention showed a portable unit with a separate tack oil tank which was provided with its own heat source and which was designed to prevent phase separation of the tack oil materials. While this apparatus solved the problem of tack oil phase separation, it was still designed to be employed in a multi-component repair system.
The present invention has as its object to provide a portable apparatus for dispensing a new type of pavement repair material which eliminates many of the shortcomings present in the prior art devices and methods.
Another object is to provide an improved pavement repair process utilizing a class of repair material which eliminates the need for more complicated multi-component asphaltic repair materials, as well as the need for complicated tank, heating and valving arrangements.
Another object of the invention is to provide a apparatus for use in such a method which is simple in design and economical to manufacture.